1. Field of the Invention
The present invention relates to scroll type fluid machinery suitable to be used in air compressors, vacuum pumps, and the like.
2. Description of the Related Art
In general, one of known scroll type fluid machinery is, for example, a scroll type compressor for continuously compressing fluid such as air in a compression chamber between an orbiting scroll and a fixed scroll by driving the orbiting scroll to orbit relative to the fixed scroll by a driving source such as an electric motor (refer to, for example, Japanese Patent Application Laid-Open No. 2003-322149).
A conventional scroll type compressor of this kind comprises a cylindrical casing, a fixed scroll fixed to the casing and having a spiral wrap portion extending from an end plate, an orbiting scroll opposed to the fixed scroll, orbitably provided in the casing, and having a spiral wrap portion extending from an end plate and overlapping the wrap portion of the fixed scroll, thereby defining a plurality of compression chambers; and an eccentric thrust bearing provided between the rear side of the orbiting scroll and the casing to prevent rotation of the orbiting scroll and to receive a thrust load.
In the conventional technique, however, by the eccentric thrust bearing provided between the rear side of the orbiting scroll and the casing, a thrust load from the orbiting scroll can be received on the casing side and rotation of the orbiting scroll can be also prevented. However, the eccentric thrust bearing has a large-diameter shape and structure extending over the entire periphery on the rear side of the orbiting scroll. This leads to large occupation area (attachment space) in the casing and law workability at the time of assembly.
The present invention has been made in view of the above-mentioned conventional art problems, and an object of the present invention is to provide a scroll fluid machine using a plurality of ball coupling mechanisms, thereby realizing smaller attachment space in a casing and improved workability at the time of assembly, smoothly preventing rotation of an orbiting scroll, and capable of receiving a thrust load.